1 files changed, 59 insertions, 33 deletions

diff --git a/lib/private/Encryption/Util.php b/lib/private/Encryption/Util.php
index 371f2588289..2d7bc28129b 100644
--- a/lib/private/Encryption/Util.php
+++ b/lib/private/Encryption/Util.php
@@ -1,29 +1,9 @@
 <?php
+
 /**
- * @copyright Copyright (c) 2016, ownCloud, Inc.
- *
- * @author Bjoern Schiessle <bjoern@schiessle.org>
- * @author Björn Schießle <bjoern@schiessle.org>
- * @author Christoph Wurst <christoph@winzerhof-wurst.at>
- * @author Jan-Christoph Borchardt <hey@jancborchardt.net>
- * @author Morris Jobke <hey@morrisjobke.de>
- * @author Roeland Jago Douma <roeland@famdouma.nl>
- * @author Thomas Müller <thomas.mueller@tmit.eu>
- *
- * @license AGPL-3.0
- *
- * This code is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License, version 3,
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License, version 3,
- * along with this program. If not, see <http://www.gnu.org/licenses/>
- *
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
  */
 namespace OC\Encryption;
 
@@ -70,7 +50,7 @@ class Util {
 	protected $config;
 
 	/** @var array paths excluded from encryption */
-	protected $excludedPaths;
+	protected array $excludedPaths = [];
 	protected IGroupManager $groupManager;
 	protected IUserManager $userManager;
 
@@ -94,7 +74,7 @@ class Util {
 		$this->config = $config;
 
 		$this->excludedPaths[] = 'files_encryption';
-		$this->excludedPaths[] = 'appdata_' . $config->getSystemValue('instanceid', null);
+		$this->excludedPaths[] = 'appdata_' . $config->getSystemValueString('instanceid');
 		$this->excludedPaths[] = 'files_external';
 	}
 
@@ -105,7 +85,7 @@ class Util {
 	 * @return string
 	 * @throws ModuleDoesNotExistsException
 	 */
-	public function getEncryptionModuleId(array $header = null) {
+	public function getEncryptionModuleId(?array $header = null) {
 		$id = '';
 		$encryptionModuleKey = self::HEADER_ENCRYPTION_MODULE_KEY;
 
@@ -310,11 +290,8 @@ class Util {
 		if (count($root) > 1) {
 			// detect alternative key storage root
 			$rootDir = $this->getKeyStorageRoot();
-			if ($rootDir !== '' &&
-				0 === strpos(
-					Filesystem::normalizePath($path),
-					Filesystem::normalizePath($rootDir)
-				)
+			if ($rootDir !== ''
+				&& str_starts_with(Filesystem::normalizePath($path), Filesystem::normalizePath($rootDir))
 			) {
 				return true;
 			}
@@ -327,7 +304,7 @@ class Util {
 
 			// detect user specific folders
 			if ($this->userManager->userExists($root[1])
-				&& in_array($root[2], $this->excludedPaths)) {
+				&& in_array($root[2] ?? '', $this->excludedPaths)) {
 				return true;
 			}
 		}
@@ -360,4 +337,53 @@ class Util {
 	public function getKeyStorageRoot(): string {
 		return $this->config->getAppValue('core', 'encryption_key_storage_root', '');
 	}
+
+	/**
+	 * parse raw header to array
+	 *
+	 * @param string $rawHeader
+	 * @return array
+	 */
+	public function parseRawHeader(string $rawHeader) {
+		$result = [];
+		if (str_starts_with($rawHeader, Util::HEADER_START)) {
+			$header = $rawHeader;
+			$endAt = strpos($header, Util::HEADER_END);
+			if ($endAt !== false) {
+				$header = substr($header, 0, $endAt + strlen(Util::HEADER_END));
+
+				// +1 to not start with an ':' which would result in empty element at the beginning
+				$exploded = explode(':', substr($header, strlen(Util::HEADER_START) + 1));
+
+				$element = array_shift($exploded);
+				while ($element !== Util::HEADER_END && $element !== null) {
+					$result[$element] = array_shift($exploded);
+					$element = array_shift($exploded);
+				}
+			}
+		}
+
+		return $result;
+	}
+
+	/**
+	 * get path to key folder for a given file
+	 *
+	 * @param string $encryptionModuleId
+	 * @param string $path path to the file, relative to data/
+	 * @return string
+	 */
+	public function getFileKeyDir(string $encryptionModuleId, string $path): string {
+		[$owner, $filename] = $this->getUidAndFilename($path);
+		$root = $this->getKeyStorageRoot();
+
+		// in case of system-wide mount points the keys are stored directly in the data directory
+		if ($this->isSystemWideMountPoint($filename, $owner)) {
+			$keyPath = $root . '/' . '/files_encryption/keys' . $filename . '/';
+		} else {
+			$keyPath = $root . '/' . $owner . '/files_encryption/keys' . $filename . '/';
+		}
+
+		return Filesystem::normalizePath($keyPath . $encryptionModuleId . '/', false);
+	}
 }